MONTPELIER — A new report by a group working to get mercury out of the environment says Vermont leads the nation in efforts to collect mercury thermostats and keep them out of the waste stream.

The Mercury Policy Project and Vermont Public Interest Research Group joined in releasing figures showing that Vermont and Maine are the nation’s leaders because they require manufacturers to pay $5 to contractors and homeowners who return mercury-added thermostats, resulting in significantly higher collection rates.

“It’s clear that a financial incentive, coupled with good education and outreach, has resulted in Vermont having one of the highest per-capita thermostat collection rates in the country,” said Michael Bender, director of the international Mercury Policy Project.

Collections jumped after Vermont’s bounty went into effect, and the state rose to first in the nation for collection in 2011.

In the first year of the program, 1,890 thermostats were turned in, the Burlington Free Press reported. In the following two years, more than 3,300 were collected.

Preliminary numbers suggest about 3,200 were collected in 2012, said Gary Gulka of the state’s Department of Environmental Conservation.

“We certainly believe that the cash incentive has had an impact,” Gulka said.

The biggest thermostat manufacturers discontinued making thermostats containing mercury in 2010. Many homeowners still have functioning mercury thermostats that can last 20 years or longer, Bender said.